JPH02175674A - Joined body of ceramics and metallic body and method for joining thereof - Google Patents

Abstract

PURPOSE:To obtain a joined body capable of improving joining strength and preventing cracking by providing a void structure having a specific void width around the ends of a metallic body and joining ceramics to the metallic body. CONSTITUTION:In a method for joining ceramics to a metal, a void structure having 0.005-2mm void width around the ends of a metallic body is provided. Both are preferably joined by using either of a method (a) for heating the ceramics and metallic body in an inert gas atmosphere, such as nitrogen gas, or vacuum atmosphere and forming bonds with the mutual diffusion of an oxide layer on the surface of the metallic body and solder (direct method) and a method (b) for interposing a soldering material prepared by mixing an active metal, such as Ti or Zr, with a metal, such as Ag, Cu, Ni or Sn, forming a low-melting alloy or forming the alloy between the ceramics and metallic body and thermally contact bonding both (active metal method).

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides ceramics, a metal body, and a Q-joint body.
The present invention relates to a joined body of a ceramic and a metal body, characterized in that the gap width around the end of the metal body is 0.005 mm to 2 mm.

<Prior Art> Ceramics generally have characteristics such as heat resistance, wear resistance, high electrical resistance, and hardness.

Bonded bodies made by bonding ceramics with these characteristics and metal bodies are often used in electronic parts, mechanical parts, and the like. However, ceramics and metal bodies have different atomic charges. The platform used to join these ceramics and metal bodies, the chemical properties such as reactivity, and the physical properties such as coefficient of thermal expansion, differ greatly. Ceramics and metal bodies, which have different properties, When the materials are heated to a high temperature and then cooled to join, thermal stress is generated due to the difference in thermal expansion coefficients.This becomes residual stress.

This residual stress reduces the joint strength. In order to reduce this residual stress and prevent a decrease in combined strength, methods for joining ridges have been proposed. That is, a method in which ceramics and a metal body are heated in an inert gas atmosphere such as nitrogen gas or in a vacuum atmosphere, and a bond is formed by mutual diffusion of the oxide layer on the surface of the metal body and the solder (direct bonding method). Also, Ag+ Cu, Ni, which forms low melting point alloys with active metals such as Ti and Zr.
A method in which a brazing filler mixture or alloy of metals such as Sn is interposed between a whole ceramic and a metal body and heated and pressed together in an inert gas atmosphere or vacuum atmosphere (active metal method), and a ceramic ζ metallized layer Many proposals have been made, such as a method (metallization method) of joining ceramics having this metallized layer and a metal body with a metal solder, but by heating and then cooling the joined body, The disadvantages of reduced bonding strength and cracks in the bonded body have not yet been resolved.

<Problems to be Solved by the Invention> An object of the present invention is to improve the bonding strength of the bonded body by reducing the total residual stress generated in the ridge body when ceramic and metal bodies are bonded, and to prevent cracks in the bonded body. The aim is to prevent this from occurring at all.

In particular, the objective is to completely improve thermal shock strength, that is, durability against repeated heating.

<Means for Solving the Problems> The present inventors have studied various ways to improve the above-mentioned drawbacks, and as a result, the present inventors have developed a method for improving the above-mentioned drawbacks. We have discovered a bonded body of ceramics and a metal body that is characterized by having a structure.

Hereinafter, non-invention will be explained in detail.

"Ceramics" as used in the present invention is not particularly limited, but includes oxide ceramics and non-oxide ceramics. Oxide-based ceramics include, for example, alumina (Adz
es), magnesia (MgO) and silicone (Zr
02), among which alumina is preferred.

Examples of non-oxide ceramics include aluminum nitride (AA!
N), silicon carbide (SiC) and silicon nitride (8i3N4)
Among them, aluminum nitride and silicon carbide are preferred.

The "metal body" as used in the present invention refers to copper (
Copper (Cu), nickel (Ni), and alloys mainly composed of these metals are preferred.

In the present invention, the "void structure around the end of the metal body" refers to any void structure 'l!' as long as the ceramic and the area around the end of the metal body are not substantially bonded to each other. - May have. Possible structures include, for example, cutting the edges of the metal body to create a groove-like structure, or using chemicals that corrode metals, such as ferric chloride water bath liquid and ammonium persulfate, to create a groove-like structure around the edges of the metal body. There are void structures obtained by corroding the edges of the metal body, and void structures obtained by not applying or placing bonding materials such as active metal brazing materials around the edges of the metal body. A void structure obtained by corrosion is preferred.

In addition, the "void part" in the non-invention is the length of the circumference of the metal body where the ceramic and the metal body are not bonded when the bonded body is viewed from above. -2,
(ll-(3) part 3, and this gap is 0.0
At 051111 or lower and 2 Dragon or higher, there is almost no improvement in thermal shock strength. Therefore, the gap is 0.005 vr
Preferably m to 2 mm, more preferably 0.01 m
For m~1, % is preferably 0.02 T! LM~0.5
It is mm.

Furthermore, the "nitrogen gap depth" as used in non-inventive terms refers to the depth between the ceramic and the metal body and a certain gap when the bonded body is viewed cross-sectionally. , (11~(
3). Although this void depth is not particularly limited, it is preferably 0.5 μ to 20 μ, more preferably 1 μ to 10 μ.

There is no limit to the percentage of the corrugation method used in the present invention, but for example, what about ceramics and metal bodies? A method in which a bond is formed by mutual diffusion of the oxide layer on the surface of the metal body and the solder by heating in an inert gas atmosphere such as nitrogen gas or a vacuum atmosphere (direct 4-coupling method). In addition, a brazing filler metal made of a mixture or alloy of binder metals such as Ti and Zr and an% of Ag@Cu + Ni, which forms a low-melting point alloy, is interposed between the ceramic and the metal body and placed in an inert gas atmosphere or vacuum. There is a method of heating soil in an atmosphere (active metal method), and a method of joining ceramics with a metal body using metal solder (metallizing method). The direct 4-coupling method and the active metal method are preferred.

Specifically, the direct 4-coupling method used in the invention involves placing the metal body on ceramics again, placing it in a heating furnace, and reducing the oxygen concentration to 2+jppm in order to prevent excessive oxidation of the metal body.
5 seconds to 15 seconds at a maximum heating temperature of 1060℃ to 1083℃ in an inert atmosphere or vacuum atmosphere adjusted as follows.
This is a method of heating for a minute and then cooling to obtain a bonded body. In addition, the active metal method involves uniformly kneading activated gold filler in the form of whole foil, powder, or powdered gold binder on the bonding surface of ceramics and metal bodies, and then screen-printing this paste. Place in heating furnace ζζ, maximum heating temperature 1i in inert atmosphere or vacuum level -10-2rorr or less atmosphere
This is a method of heating at a temperature within 700 to 950°C for a heating time of 3 to 60 minutes, and then cooling to obtain a bonded body.

Although there are no restrictions on the active metal brazing filler metal, it is possible to bond them by heating at a relatively low temperature. Silver (Ag), copper (Cu
), mixtures of titanium (T1) or titanium hydride (TiH), silver (Ag), copper (Cu), nickel (Ni)
, titanium (T1) or titanium hydride (T i H) mixture system, silver (Ag), @(Cu), tin (Sn), titanium or titanium hydride (TiH) mixture system, *(Ag) )
, nickel (Ni), titanium or titanium hydride mixtures, and silver (Ag), copper (Cu), zirconia (Zr)
) or a mixture system of copper, nickel, titanium or titanium hydride is preferred.

Hereinafter, a more specific explanation will be given with reference to Examples.

Example A (Preparation of joined body) Example 1, ff1l2L 58 normal angle, thickness 0.3 By etching the edge of the previous phosphorus-deoxidized copper substrate with a ferric chloride water bath solution, A groove with a gap depth of 2 μm was formed as shown in Figure 3.

Next, the copper substrate and an alumina substrate (pure #96%) with a 64 angle angle and a thickness of 0.635 mm were cleaned with acetone and degreased, and then the copper substrate was placed on both sides of the alumina substrate, and a tunnel type The mixture was placed in a heating and firing furnace, and then nitrogen gas was introduced into the firing furnace while adjusting the flow rate, and nitrogen gas was supplied so that the oxygen concentration in the furnace was 1 ppm. In this nitrogen atmosphere, the heating speed fr was set at 300°C/min, and the maximum heating temperature (
1063±0.5° C.) for 10 minutes, and then cooled to obtain a bonded body (hereinafter, this bonded body will be referred to as a bonded body, Ryo 1, and will be used as an example).

A copper substrate with no grooves formed around the open end of the bonded body tK 1 is placed on the alumina substrate, and a bonded body 46 is formed.
Bonding was carried out under the same conditions as 1 to obtain a bonded body (hereinafter this bonded body will be referred to as gold bonded body 2 and will be used as a comparative example).

Implementation 1'-2 The periphery of the end of the joint body height 2 is immersed in ammonium perphosphate to form a joint body having a gap with a gap width of approximately 10 to 20 μm and a desired gap depth of approximately 1 μm (hereinafter referred to as This will be referred to as Meeting Body High School 3 and will be used as an example).

Example 3, Comparative Example-2 The total gap around the edge of a tough pitch electrolytic steel substrate with a 58 angle and a thickness of 200 μm] 1.5 angle, a gap depth of 3 μm, and YJ
7.1 Cutting was done.

Next, the copper plate and a 64 mm square, 0.935 mm thick alumina substrate (purity 96%) were cleaned with acetone, degreased, and placed on the alumina substrate, followed by tunnel heating and firing. It was placed in a furnace, and nitrogen gas was introduced into the firing furnace, and the nitrogen gas was supplied so that the oxygen concentration in the furnace was 0.2 ppm. In this nitrogen atmosphere, the heating speed was set to 300°C/min, the maximum heating temperature was 1072°C, and the bonded body was heated for 5 minutes and then cooled. use).

Further, a bonded body obtained at a bonded body height of 4 and having a tough pitch without forming a gap around the edge of the copper-deposited substrate is referred to as A5, and is used as a comparative example.

Example 4 The periphery of the end of the bonded body A5 was immersed in ammonium perphosphate to obtain a bonded body with an alumina substrate having a peripheral gap width of approximately 15 to 30 μm and a gap depth of 3 μm (hereinafter, this bonded body will be referred to as Junction factory 6
and used as an example).

Examples 5 to 6, Comparative Example 3 68.891 silver powder, 26.7 g of copper powder, and 4.5 I of titanium powder, which are powders of 326 mesh or less, were weighed, and to this was added 39 g of isobutyl methacrylate and 30 g of terpineol.
The mixture was mixed and ground in a ball mill to form a paste 'ix. Next, after cleaning and degreasing a 0.635 mm thick aluminum nitride substrate and a 20 m square, 300 μm thick oxygen-free steel substrate with trichloride and acetone, the above paste l-screen printing was performed. It was printed on a formula aluminum substrate with dimensions of 18.5 m7rr square and 40 tt so that the void space was 0.75mm, and dried in a hot air dryer at 120°C for 10 minutes. A copper substrate was placed on the paste-applied side of the aluminum nitride substrate as shown in Figure 4, and this was placed in a vacuum heating firing furnace to form a 5 x 10''-'To
After heating with 850-CX for 10 minutes under a vacuum of
used as an example).

Further, it was printed on the paster aluminum nitride substrate used in the bonded body 711; 7 to a size of 20 mrn square and 40 μm thick. A copper substrate was placed on the substrate in the same manner as in the connection body 7, and the bonded body was heated under the same conditions as in the pot 7 to form a bonded body with the steel substrate and the aluminum oxide (with no void packing). Ta(
This conjugate will hereinafter be referred to as conjugate 58 and will be used as a comparative example).

A bonded body was obtained which shouldered a gap of approximately 5μ in diameter (hereinafter, this bonded body will be referred to as bonded body &9 and will be used as an example).

Example B (Evaluation of zygote) After cooling each of 10 sheets of zygotes &1 to 9 obtained in Example 2 at -50°C for 30 minutes, they were heat-treated at 150°C for 30 minutes. A 100 cycle test was conducted with this repetition as one cycle. Thereafter, the number of joined bodies in which cracks occurred was determined, and the results are shown in Table 11.

As shown in Table 1, the bonded body thermal shock test made by Tomei was extremely strong, no cracks appeared, and the bonding strength was also strong.

[Brief explanation of the drawing]

1 and 3 are cross-sectional views of the joined body and metal body of the present invention, and FIG. 2 is a plan view thereof. FIG. 4 is a sectional view of the connecting body 7 obtained in Example 5. In Figures 1 to 4, 1 is a metal body, 2 is a ceramic body,
Reference numeral 3 indicates a void structure, and reference numeral 4 indicates a bonding surface between the metal body and the ceramic. Further, 5 in FIG. 4 indicates paste. Figure-2 Figure-2 Figure-3 Figure-4

Claims (10)

[Claims] (1) A joined body of a ceramic and a metal body, characterized in that the body has a void structure in which the width of the gap around the end of the metal body is 0.005 mm to 2 mm. (2) The conjugated body according to claim 1, wherein the conjugated body is a conjugated body by a direct bonding method. (3) The bonded body according to claim 1, wherein the bonded body is a bonded body formed by an active metal method. (4) The joined body according to claim 1, wherein the void structure around the end of the metal body is a groove. (5) The joined body according to claim 1, wherein the ceramic is alumina (Al_2O_3). (6) The joined body according to claim 1, wherein the ceramic is alumina nitride (AlN). (7) The joined body according to claim 1, wherein the ceramic is silicon carbide (SiC). (8) The joined body according to claim 1, wherein the metal body is copper or a copper alloy. (9) The joined body according to claim 1, wherein the metal body is nickel and a nickel alloy. (10) In a method for joining ceramics and a metal body, the gap width around the end of the metal body is 0.005 mm to 2 m.
A method for joining a ceramic and a metal body, characterized by having a void structure of m.